1. Technical Field
The present invention relates to liquid crystal display technical field, and more particularly, to a display improvement method of a liquid crystal display (LCD) panel and a display improvement apparatus thereof.
2. Background Art
In recent years, LCDs gradually replace conventional Cathode Ray Tube (CRT) displays because of their merits of small volume, light weight and high display quality and so on. As the LCD is continuously applied, users' demand for a view angle of the LCD is gradually increased. Thus, a wide-angle LCD provided with a wider viewable angle is developed, such as a VA-type LCD or the like.
CNCA/CTS 0019-2013 CESI Specification prescribed in “Ultra High-Definition Display Certification Technical Specifications” provides nine standards for a chrominance viewing angle, wherein the chrominance viewing angle is a horizontal viewing angle when a chromatic aberration is 0.02 in a center of a screen. Currently, there is still a problem of a color bias while looking at the wide-angle LCD from a side view, so that the chrominance viewing angle is too small to satisfy the requirement of the users for a larger view angle of the LCD.
In particular, FIG. 1 shows gamma curves of color sub-pixels acquired in cases of a front view and a side view. As shown in FIG. 1, a gray-scale inversion phenomenon apparently exists in a gamma curve of each color sub-pixel (i.e., a red sub-pixel, a green sub-pixel, a blue sub-pixel, or a white sub-pixel) acquired in a case of the side view (e.g., observing the LCD panel from an angle of 60° with respect to a vertical direction of the LCD panel), and such gamma curve has a great difference from a gamma curve of each color sub-pixel acquired in a case of the front view (e.g., observing the LCD panel from an angle of 0° with respect to the vertical direction of the LCD panel). That is, the color difference is great, so that the viewing angle is too small.
FIG. 2 shows gamma curves of color sub-pixels acquired in a case of the side view after a BH/BL conversion is performed. The BH/BL conversion refers to that all the blue sub-pixels on the LCD panel are divided into blue sub-pixel pairs each consisting of two blue sub-pixels, and a first blue sub-pixel of each blue sub-pixel pair is provided with a high gray-scale value, and a second blue sub-pixel thereof is provided with a low gray-scale value. As shown in FIG. 2, a gray-scale inversion phenomenon existed in the gamma curve of each color sub-pixel (i.e., a red sub-pixel, a green sub-pixel, or a blue sub-pixel) acquired in a case of the side view after the BH/BL conversion is performed, is greatly reduced. However, the gray-scale inversion phenomenon still exists even after the BH/BL conversion is performed due to practical limitations such as data measurement errors, circuit signal control limit, prevention of brightness flickering in a space and so on. Thus, the gamma curve in a case of the side view cannot overlap with or have a small difference from the gamma curve of the color sub-pixel acquired in a case of the front view. Therefore, a color difference still exists, and a requirement of the users for a large viewing angle cannot be satisfied.